Top pickup transfer guide for endless chain drive

ABSTRACT

A series of work arms are pivotally mounted on a chain drive and each has a pair of vertically spaced flanged wheels which roll against vertical track elements to hold the work arm erect as it lifts or lowers a load carried by a supporting cradle offset relative to the center of the work arm. Upper transverse track elements guide the upper wheel as it passes from one side of the chain drive to the other. To prevent the upper wheel, for example, from slipping back the wrong way during the crossover, a stop is located on each side of the center in positions where they will engage respective cradles so that, should the work arm tend to tilt too far from a vertical orientation, it will be prevented from doing so by engagement of one or the other cradle with its respective stop.

United States Patent 72] Inventor Robert D. Lichti 3318 Warwood Road,Lakewood, Calif. 90805 [21] Appl. No. 65,862 [22] Filed Aug. 21,1970[45] Patented Dec. 14, 1971 Continuation-impart of application Ser. No.47,764, June 19, 1970. This application Aug. 21, '1970, Ser. No. 65,862

[54] TOP PICKUP TRANSFER GUIDE FOR ENDLESS CHAIN DRIVE 7 Claims, 6Drawing Figs.

[52] U.S.Cl 198/155, 198/158 [51] Int. Cl B65g 115/00 [50] FieldofSearch 198/145, 155, 158

[56] References Cited UNITED STATES PATENTS 3,547,281 12/1970 Lichti198/158 X Primary ExaminerRichard E. Aegerter Assistant Examiner-DouglasD. Watts Anorney-Beehler & Arant ABSTRACT: A series of work arms arepivotally mounted on a chain drive and each has a pair of verticallyspaced flanged wheels which roll against vertical track elements to holdthe work arm erect as it lifts or lowers a load carried by a supportingcradle offset relative to the center of the work arm. Upper transversetrack elements guide the upper wheel as it passes from one side of thechain drive to the other. To prevent the upper wheel, for example, fromslipping back the wrong way during the crossover, a stop is located oneach side of the center in positions where they will engage respectivecradles so that, should the work arm tend to tilt too far from avertical orientation, it will be prevented from doing so by engagementof one or the other cradle with its respective stop.

TOP PICKUP TRANSFER GUIDE FOR ENDLESS CHAIN DRIVE This is acontinuation-in-part of Ser. No. 47,764, filed June 19, 1970.

The invention relates to a vertical automated storage system in whichplatforms travel about on an endless link drive and wherein an endlesschain drive having work arms are adapted to pick up platforms at onelocation in their path of travel and move them from one position to thenext. The general arrangement is disclosed in U.S. Pat. Nos. 3,278,052,3,424,321, and patent applications Ser. No. 737,647, filed June 17,1968, Ser. No. 873,358, filed Nov. 3, 1969, and Ser. No. 47,764 filedJune 19, 1970.

Although in the general arrangement of chain drive for devices of thekind herein made reference to structure has been included for holdingthe work arm in a desired position as it passes over the top of its pathof travel from one side of the device to the other, such meansheretofore made use of has been somewhat complicated and expensive,difficult to maintain and service, and, under some circumstances, not asdependable for long periods of use as might be desired.

It is therefore among the objects of the invention to provide a new andimproved top pickup transfer for an endless chain drive which is verypositive in its construction and operation, sufficiently so that it isfail-safe.

Another object of the invention is to provide a new and improved toppickup transfer guide for an endless chain drive which is very simple inits operation and which is such that it makes double use of elementsalready present for another purpose by utilizing their character andlocation to prevent the work arm from shifting to an unwantedorientation.

Still another object of the invention is to provide a new and improvedpickup transfer guide for an endless chain drive in which stops are sopositioned that they engage recesses on the work arm in a relationshipsuch that either one or both stops are compelled to be in engagementwith the recesses at all positions of travel, thereby to make certainthat the work arm cannot inadvertently shift to an unwanted orientation.

With these and other objects in view, the invention consists in theconstruction, arrangement, and combination of the various parts of thedevice, whereby the objects contemplated are attained, as hereinafterset forth, pointed out in the appended claims and illustrated in theaccompanying drawings.

In the drawings:

FIG. 1 is a side elevational view of the chain drive with portions shownin section, showing five work arms in various different positions.

FIG. 2 is a fragmentary longitudinal sectional view on the line 22ofFIG. ll.

FIG. 3 is a fragmentary vertical sectional view of the uppermost end ofthe chain drive with the work arm in one position during passover.

FIG. 4 is a fragmentary vertical sectional view similar to FIG. 3showing the work arm in a position successive to the position of FIG. 3.

FIG. 5 is an enlarged fragmentary side elevational view showing detailsofone of the stops.

FIG. 6 is a fragmentary vertical sectional view on the line 6-6 of FIG.5.

In an embodiment of the invention chosen for the purpose ofillustration, there is shown a frame indicated generally by thereference character 10 having vertical side members 11 and 12, a lowercross member 13 and transverse webs M and 15 having respective topportions 14' and I5. Transverse channel sections 16 and I7 serve asmeans for anchoring the transverse webs in position, as shown in FIG. 2.Plates l8 and 19, constituting additional supporting structureassociated with the frame, are shown in FIG. 2.

An endless drive chain 20 is shown extending over an upper sprocket 21and a lower sprocket 22, the sprockets being rotatably mounted on theframe by respective shafts 23 and 24. A suitable source of power (notshown) is acting through a drive shaft 25, a sprocket 26, a drive belt27 engaging with a sprocket 28 on an idler shaft 29, passing the driveto a sprocket 30, a drive belt BI and a driven sprocket 32, the drivensprocket 32 being keyed to the same shaft 24 as is the lower sprocket 22which accommodates the drive chain 20.

On the drive chain 20 is a series of work arms 35, 36, 37, 38, and 39,each work arm being identical such that a description of the work arm36, for example, will suffice for the others. The work arm is attachedat its lower end by means of a pivot pin 40 to a junction of adjacentlinks of the drive chain 20. In the chosen embodiment there are in facttwo of the chains 20 between which is mounted the am 36 and the otherarms identified heretofore. Bushings 41 and 42 assist in pivotallymounting the arm 36 on the pivot pin 40, as shown in FIG. 2.

At the lower end of the work arm 36 is a fishtail slot 43 which, byengagement with a pin 44 in a section of the frame 10, when the arm 36is at its lowermost, position serves to swing the arm from a position oftilt like that of the arm 38 in FIG. 1 to that of the arm 39 in FIG. 1on the opposite side, assuming the travel of the chain 20 to be in acounterclockwise direction. For travel in an opposite direction the tiltwould be in a reverse direction.

The work arm 36 in common with all of the other work arms is providedwith two cradles and 51 which are upwardly facing recesses on oppositesides of a vertical centerline. The cradles 50 are shown in engagementor potential engagement with rods 52 and 53 on the right side of thedevice as viewed in FIG. ll. Similar rods 54 and 55 on the left side areshown in engagement or potential engagement with the cradles 51. Thework actually performed by the work arms is accomplished by the work armbeing moved into engagement with one or another of the rods whichsupport an appropriate load (not shown) so that the load may be moved upor down, as the case may be, depending upon the direction of travel ofthe respectively engaged work arrn.

For maintaining each work arm in a vertical position during its upwardor downward travel, as viewed in FIG. ll, an inside face 56 of the sidemember 11 of the frame serves as a vertical track element. Similarly, aninside face 57 of the side member I2 serves as a track element on theopposite side. To utilize the track elements 56 and 57 flanged wheels 58and 59 are rotatably mounted upon a shaft 60 at the upper end of thework arm 36, for example. The wheels are adapted to roll on either thetrack element 56 or 57 depending upon where the work arm chances to be.For guiding the lower end of the work arm use is made of rollers 61 and62 which are concentric with the bushings 41 and 42 and the pivot pin40. The rollers 6i and 62 likewise are adapted to roll upon the trackelements 56 and 57, and when in such position, as shown by the work arms35 and 37 in FIG. I, the work arm at that stage of travel is held in avertical position so that the rod 53 is firmly supported by the work arm35 as is the rod 54 supported by the work arm 37.

As the work arm approaches the top of its lifting path the work arm nextbelow is brought into engagement with its respective rod and the upperwork arm can be released. This is accomplished by movement of the chain20 at the point where it is in engagement with the pivot pin 40 awayfrom vertical alignment causing the work arm to tilt in a directionmoving the cradle 50 out from under the rod in which it is engaged.

It is important, however, that this tilt be limited in that the work armmust be carried from one side of the structure to the other at the upperend of its path of travel. For guiding the upper end of the work armfrom one side of the device to the other, there are provided trackelements 63, 63 formed on the upper portions 14 and 15' of therespective webs l4 and 15, the track element 63 being transverse andsloping upwardly toward junctions 64, 66' with oppositely sloping trackelements 63, 65'.

Lower members 66, 66 of the track elements 63, 63' serve to confine theflanged wheels in position. Similarly, on the opposite side are lowermembers 67, 67' which serve a comparable purpose.

To accommodate the space occupied by the wheels 58 and 59 in their pathof travel from one side of the frame to the other, struts 70 areprovided on front and back sides of the frame at the right of thestructure, as viewed in FIG. 1, and similar struts 71, 71 are providedon the left-hand side. A recess 72 in the strut 71 and a similar recess73 in the strut 71 demonstrate how the way is cleared for the passage ofthe wheels from one side to the other. Center struts 74 are similarlyformed.

To make certain that the webs hold their upright orientation as theypass over the top of their path of travel, there are provided stops 75and 76, fastened to one of the webs such for example as the web part14', by means of bolts 77, as shown in FIGS. and 6, the stop memberbeing positioned by means of spacers 78 and 79. To provide a cushioningeffect, there is employed an additional stop 80 which may be made ofsome durable plastic material, and which projects out slightly furtherthan the stops 75, 76 so as to absorb initial impact, thereby to cushionthe operation. The stop 80 is adapted to abut against a flange 81effectively welded to the adjacent web. The arrangement of partsassociated with the stop 76 is the same as that for the stop 75 exceptfor one being oriented in a direction reverse with respect to the other.

In operation as the work arm 36, for example, moves toward the top ofits path of travel it is tilted slightly clockwise by reason of the factthat the pivot pin 40 is moved toward the center slightly in advance oftravel of the wheels 58 and 59 as they move along and are guided by thetrack elements 63, 63. Some short distance before the wheels enter thejunctions 64, 64', which are in effect recesses, the cradle 50 engagesthe stop 75 in the position shown in FIG. 3. As the chain continues tomove, the pivot pin 40 continues to be moved and, because the flangedwheels are temporarily detained at the junctions 64, 64, the work arm 36will commence being tilted from the position of FIG. 3 to the positionof FIG. 4. Intermediate these two positions, however, the cradles 50 and51 will have the relative positions shown at the top of FIG. 1 whereinboth are in potential engagement with the respective stops 75 and 76. Inthis position the work arm is held in and cannot depart from thevertical position there shown.

As the chain 20 continues to move, the work arm 36 will be tilted to theposition of FIG. 4 wherein the cradle 50 becomes disengaged from thestop 75 and the cradle 51 becomes engaged with the stop 76. Clearly, inthis position the upper end of the work arm cannot move in a contrarydirection, namely a direction from left to right as viewed in FIG. 4,because of being prohibited by the stop 76. As the chain continues tomove counterclockwise, although the work arm is then moved downwardlysufficient to disengage the cradle 51 from the stop 76, by this time thewheels are traveling down the track elements 65,65 to a point where theyoverlie the lower members 67, 67' and the top of the work arm is stillprevented from inadvertently tilting in the wrong direction.

Ultimately, the chain 20 moves the work arm 36 far enough down so thatthe wheels 58, 59 engage the track element 57 as do also the rollers 61,62. This position is shown by the work arm 37 in FIG. 1. Hence, when forexample one of the rods 54 may be in engagement with the cradle 51 atthis point, the engagement will be maintained as the work arm movesdownwardly, to follow through on the example previously undertaken, orshould it be moved in an upward direction. As the work arm continuesdownwardly to the position shown by the work arm 38 in FIG. I, thedirection of travel of the chain 20 is such that it will pull the workarm into the tilted position shown, thereby to release the cradle 51from engagement with the adjacent rod, until finally the work arm ismoved clear because of being drawn inwardly by the direction of chaintravel until the fishtail slot 43 engages with the pin 44 to flop thework arm over to the position of the work arm 3.9 in FIG.

1. From this point the operation is substantially as heretoforedescribed.

Travel of the chain 20 in an opposite or clockwise direction merelycauses all parts of the apparatus to operate in reverse,

but in substantially the same basic fashion.

The unit comprising in the main, the side members 11 and 12, theinterconnecting webs 14 and 15 and corresponding transverse lowerelements is designed to be slidably mounted in the overall structure(not shown) to allow it to move up or down about Va-inch. This is doneto prevent any error or wear in the bearings from causing undue forceson the guide.

While the invention has herein been shown and described in what isconceived to be a practical and efiective embodiment, it is recognizedthat departures may be made therefrom within the scope of the invention,which is not to be limited to the details disclosed herein but is to beaccorded the full scope of the claims so as to embrace any and allequivalent devices.

Having described the invention, what is claimed as new in support ofLetters Patent is:

1. A top pickup guide for an endless chain driven actuator, said guidecomprising a frame,

upper and lower vertically spaced sprockets on said frame,

a vertically mounted power-operated endless drive chain extending oversaid sprockets,

a plurality of work arms each pivotally mounted adjacent its lower endon said chain at spaced intervals relative to the others,

vertically disposed traveler means on said work arm and a cradle on eachwork arm on each side of said traveler means,

horizontally spaced parallel vertically extending track elements on saidframe and transverse track elements extending from the verticallyextending track elements to a centrally located junction,

said track elements and said traveler means being in travelingengagement,

and a pair of stops on the frame on respective opposite sides of saidjunction for preventing displacement of said work arm from asubstantially vertical relationship, said stops being at substantiallythe same elevation and spaced one from the other a distancesubstantially equal to the distance between said cradles, whereby uponengagement of one cradle with one of said stops unwanted displacement ofthe lower portion of said work arm is inhibited by engagement of theother cradle with the other stop.

2. A top pickup guide as in claim 1 wherein the traveler means comprisesvertically spaced independent rollers in rolling engagement with saidtrack elements.

3. A top pickup guide as in claim 1 wherein said cradles are recesseddepressions and each said stop includes a shoulder which enters therespective depression.

4. A top pickup guide as in claim 1 wherein there is a cushion on eachstop engageable by a portion of said cradle to diminish noise andvibration.

5. A top pickup guide as in claim 2 wherein said transverse trackelements comprise upper and lower members forming a channel therebetweenfor confinement of the upper of said rollers.

6. A top pickup guide as in claim 2 wherein said junction is an upwardlyrecessed junction substantially midway between opposite sides and theupper of said rollers is adapted to be temporarily detained in saidrecessed junction while the lower of said rollers passes from one sideof a vertical centerline to the other.

7. A top pickup guide as in claim 1 wherein the cradles on one side ofthe work arm extend outwardly beyond the frame and the cradles on theopposite side of the work arms extend beyond the frame on the oppositeside.

1. A top pickup guide for an endless chain driven actuator, said guidecomprising a frame, upper and lower vertically spaced sprockets on saidframe, a vertically mounted power-operated endless drive chain extendingover said sprockets, a plurality of work arms each pivotally mountedadjacent its lower end on said chain at spaced intervals relative to theothers, vertically disposed traveler means on said work arm and a cradleon each work arm on each side of said traveler means, horizontallyspaced parallel vertically extending track elements on said frame andtransverse track elements extending from the vertically extending trackelements to a centrally located junction, said track elements and saidtraveler means being in traveling engagement, and a pair of stops on theframe on respective opposite sides of said junction for preventingdisplacement of said work arm from a substantially verticalrelationship, said stops being at substantially the same elevation andspaced one from the other a distance substantially equal to the distancebetween said cradles, whereby upon engagement of one cradle with one ofsaid stops unwanted displacement of the lOwer portion of said work armis inhibited by engagement of the other cradle with the other stop.
 2. Atop pickup guide as in Claim 1 wherein the traveler means comprisesvertically spaced independent rollers in rolling engagement with saidtrack elements.
 3. A top pickup guide as in Claim 1 wherein said cradlesare recessed depressions and each said stop includes a shoulder whichenters the respective depression.
 4. A top pickup guide as in Claim 1wherein there is a cushion on each stop engageable by a portion of saidcradle to diminish noise and vibration.
 5. A top pickup guide as inClaim 2 wherein said transverse track elements comprise upper and lowermembers forming a channel therebetween for confinement of the upper ofsaid rollers.
 6. A top pickup guide as in Claim 2 wherein said junctionis an upwardly recessed junction substantially midway between oppositesides and the upper of said rollers is adapted to be temporarilydetained in said recessed junction while the lower of said rollerspasses from one side of a vertical centerline to the other.
 7. A toppickup guide as in claim 1 wherein the cradles on one side of the workarm extend outwardly beyond the frame and the cradles on the oppositeside of the work arms extend beyond the frame on the opposite side.